Synthetic plastic pad



June 1, 1948.

R. w. FORNWALT 2,442,405

SYNTHETIC PLASTIC PAD Filed July 3, 1946 Patented June 1, 1948 UNITEDSTATES PATENT OFF! CE SYNTHETIC PLAs'Tio P'A-D Ralph W. Forneau,Lebanon, Pa. Application July s, 1946, Semi No. than 2 claims. (01.66-1) This invention relates to an article "of manufacture comprising a,synthetic plastic material having a special surface formed thereon; anda method of surfacing and re-sUrfacing synthetic plastic materials. Moreparticularly, the invention relates to a pad of thermoplastic materialconsisting of a polymerized synthetic resin, and method of imparting aspecial surface to such material.

It is a special object of the invention to provide a creasing pad ofthermoplastic polymerized synthetic resin, which pad has a ratherspecial application in manufacture of nylon stockings, and to provide anovel and effective method of imparting to such pad a surface whichmakes it especially adaptable to the stated purpose.

Other and further objects, features and advantages will be apparent fromthe description which follows, read in connection with the accompanyingdrawings in which Figure 1 is a perspective View of a slab or pad ofthermoplastic material having a, glossy surface as received from themanufacturer;

Figure 2 illustrates the method of imparting the hereinafter describedspecial surface to the pad of Figure 1; and

Figure 3 is a perspective view of the finished article of manufacture ofthe present invention.

In order to facilitate an understanding of the invention, reference ismade to the embodiment thereof shown in the accompanying drawings, anddetailed descriptive language is employed. It will nevertheless beunderstood that no limitation of the invention is thereby intended andthat various changes and alterations are contemplated such as wouldordinarily occur to one skilled in the art to which the inventionrelates.

In the manufacture of stockings, the leg portion, including the sides ofthe heel portion, are knitted on a legging machine, after which the footis knitted on in a footing machine. Before the stocking is sent to thefooting machine it is topped, which involves creasing the leg portionadjacent its unfinished end or, in other Words, opening a course ofloops in order that they may be fitted over a row of pins for purposesnot material to the present invention. This creasing is performedmanually by an operator who holds the unfinished end of the stocking legin contact with a flexible, yielding pad of material and operates uponit with a pointed instrument called a creaser.

In the case of nylon stockings it has been found that the most suitablematerial for the pad consists of a thermoplastic polymerized syntheticresin such as vinyl chloride, vinyl butyral, or polyethylene. Thismaterial, when received from the manufacturer, has a giossysurracenevertireless is somewhat tacky and provides good frictioncharacteristics for preventing the stock-'- ifi-g from slipping on thebad While it is being creased. However, after a few weeks of use thesurface of such material becomes scratched and roughened through wearand, since the scratches are parallel, the coefficient of friction ofthe material in the direction of the scratches is reduced, leading toslippage of the stocking leg on the pad which causes damage and loss.Accordingly, it has been found that after about three weeks of use thepads must be discarded even though very little of the material has beenworn away. Since thesepads are used in considerable quantities, thenecessity of discarding them after such a short period of use occasionsconsiderable economic loss.

It has been determined that by applying to the creasing pads made of theabove-named materials, a special surf-ace as hereinafter described, thelife of the pads may be doubled. Moreover, by the method of the presentinvention, when the pads become unusable they may be re-surfaced anindefinite number of times, thus vastly prolonging their period ofusefulness and effecting a considerable saving to hosiery manufacturers.

According to the method of the present invention, a creasing pad Ill,for example a pad of thermoplastic polymerized vinyl chloride, having aflexible, yielding consistency, is covered with a layer ll of closelywoven textile material such as broadcloth, percale, or the like, and ispressed with a heated fiatiron I2 for a few seconds until the surface ofthe thermoplastic material has softened and has received the impressionof the adjacent surface of the textile material. A temperature of from350 F. to 450 F. is suitable for this purpose, depending upon the lengthof the treatment and the degree of pressure applied. Preferably, onlylight pressure is applied and the material is heated to a temperature ofapproximately 400 F.

The heat and pressur are then removed, and

. the cloth layer is peeled away from the thermoplastic material leavinga surface l3 which is a replica of the surface of the textile material.This uniform, slightly roughened surface has been found to possessadmirable friction characteristics for the stated purpose, and moreover,may be used for approximately twice the length of time as a pad of theoriginal glossy material before it becomes unsuitable for use.

It is preferred to treat the original, glossy material before putting itinto use as a creasing pad, but in either case the material may beresurfaced by the described method an indefinite number of times, andthus may be used for a prolonged period before finally discarded.

The method of the present invention may be applied to any thermoplasticmaterial which possesses suitable characteristics for the stated use,namely, suitable strength, flexibility, toughness and yieldingproperties. The degree of heat and pressure applied in carrying out theabove described method may vary somewhat depending upon the materialchosen but, with the materials heretofore employed, such variation willnot exceed the range stated above.

Moreover, the described method may be employed for surfacing orre-surfacing thermoplastic materials for any desired purpose, theinvention not being limited to the production of creasing pads forhosiery manufacture.

Having thus described the invention, what is new and desired to beobtained by Letters Patent 1. As an article of manufacture, a. stockingREFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,534,527 Joseph Apr. 21, 19251,753,865 LaMont Apr. 8, 1930 1,827,127 Weamer Oct. 13, 1931 1,986,629Fenton Jan. 1, 1935 2,024,177 Mellor et a1 Dec. 17, 1935 2,341,019 CookFeb. 8, 1944

